THE UROGENITAL SYSTEM. 273 
M. urethralis (/).—This consists of fibres surrounding the 
cranial part of the urogenital sinus and the caudal parts of the 
vagina and neck of the bladder. 
Origin partly on the caudal part of the symphysis of the 
ischium, partly from the ventral surface of the urogenital sinus, 
where the fibres are attached to the corpora cavernosa clitoridis. 
The fibres pass dorsad over the surface of the sinus, and over 
the surface of the union of the vagina and neck of the bladder, 
to be inserted into the sides of the vagina and the dorsal surface 
of the urogenital sinus. 
